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Wang L.,Gold Geological Institute of China Armed Police Force | Wang L.,China University of Geosciences | Wang L.,National Research Center for Geoanalysis | Wang Y.-P.,National Research Center for Geoanalysis | And 2 more authors.
Huanjing Kexue/Environmental Science

The concentrations of Cr, Co, Ni, Cu, Zn, Pb, Cd, As and Hg in surface sediment samples of Yangtze River collected in 2007 were analyzed and evaluated. The results indicated that the concentrations of Cu, Zn, Pb, Cd, As and Hg were significantly higher than those measured in 1990s.Principal Component Analysis showed that the cumulative proportion of the first three components accounted for 86.75% of the total variable, indicating the three major sources of heavy metals were industrial and mining wastewater, weathering and erosion of rocks, and urban electroplating industry wastewater and natural sources. Geoaccumulation index (Igeo) and enrichment factors (EF) also showed that the surface sediments of the Yangtze River were not contaminated with Cr, Co and Ni, lightly contaminated with Cu, Zn, As and Hg, and majorly contaminated with Pb and Cd. The ecological hazards for the heavy metals in the sediments were evaluated with the Hakanson ecological risk index. It was concluded the ecological hazards for each metal in a descending order were Cd>Hg>As>Zn>Pb>Cu>Co>Ni>Cr. The comprehensive index of potential ecological risks for metals indicated that 36% of the 61 sites had moderate potential ecological risks. Three sites had a high potential ecological risk, namely, Chongqing site of the main Yangtze River, Zishui Dongting Lake and Xinjiang site, whereas Xiangjiang Hengyang section, Xiangjiang Zhuzhou section, Xiangjiang Dongting Lake entrance, Dongting Lake and Shunan River belonged to the areas with extremely high potential ecological risk. Source

Ge L.S.,Gold Geological Institute of China Armed Police Force | Wang Z.H.,Gold Geological Institute of China Armed Police Force | Yang G.C.,Gold Geological Institute of China Armed Police Force | Lu Y.C.,Gold Geological Institute of China Armed Police Force | Lu Y.C.,China University of Geosciences
Acta Petrologica Sinica

The Yanshanian magmatism in the northeastern part of the Shanxi Province, controlled by regional structures, occurred as northeast belt with local concentrations. These magmatic rocks, lormed in three pulses at 150 ∼ 160Ma, 130 ∼ 140Ma and 85 ∼ 127Ma, can be grouped into two suits. The former suit is comprised of granodiorite, monzongranite and coarse grain porphyritie biotite granite. The later suit is composed of diorite, granodiorite porphyry, granitic porphyry and quartz porphyry. The later suit shows close relationship to gold and basic sulfide mineralization. Most of these magmalic rocks are peraluminous and alkaline rocks with adakite affinity. These rocks belong to I-type and were evolved from same source. The formation of these granitic rocks was probably related to crust-mantle interaction triggered by lithosphere thinning of the North China Craton in Mesozoic. Related to the Yanshanian magmalic activities, mineral deposits also show concentration and multi-stage mineralization. The mineral deposit types include porphyritie Mo-Au, skarn-hydrothennal vein Au, Fe, and explosive breccia-hydrothermal quartz vein type Au or Cu-Ag, Ag-Pb-Zn deposit. Some of these types were overlapped sometimes in the same area and show spatial zone in elemental distributions. The Mo-Au mineralization was in 150 ∼ 160Ma and is related to the monzondiorile or quartz diorite, granodiorite. The Au mineralization was in 130 ∼ 140Ma, and is related to quartz diorite and quartz porphyiy. Ag and basic sulfide mineralization were in 85 ∼ 127Ma, and is related to granitic porphyry, quartz porphyry and explosive breccia rocks. Hydrothermal fluid responsible for this mineralization was soured from related magmatic activity. These metallic mineralization were genetically related to the tectonic regime transition of North China Craton in Mesozoic, lithosphere thinning, and inner land orogenesis and large scale magmatic activities. Source

Ge L.S.,Gold Geological Institute of China Armed Police Force | Ge L.S.,Chinese Academy of Geological Sciences | Deng J.,China University of Geosciences | Yang L.Q.,China University of Geosciences | And 2 more authors.
Acta Petrologica Sinica

Ailaoshan gold-polymetal ore concentration region refers to a polymetal deposits concentration area which had traditional Ailaoshan metallogenic belt as the center, its adjacent mine fields, mine area as the details. It locates at the combining zone of ancient tectonic units with different character caused by Ailaoshan composite orogeny. The evolutional process of Ailaoshan composite orogeny includes a series of complex orogenic processes such as formation of Precambrian-Early Paleozoic orogenic belt, subduction orogenesis of Late Paleozoic era, collisional orogenesis of Late Hercynian-Indosinain, and extensional orogenesis of Yanshainan-Cenozoic. Different mineralization geological environment and corresponding metallogenic system are formed in different structural-mineralization units of Ailaoshan ore concentration area. It involves the continental margin rift setting and metallogenic system in Yangtze plate of Early-Middle Proterozoic, the Ailaoshan continental margin oceanic basin rift (little oceanic basin)-suture environment and convergent continental margin metallogenic system of Middle-Late Paleozoic, the Gejiu-Wenshan compound rift basin poly-cycle evolvement and compound metallogenic system, the Jinping "stabilization" continental margin blocks environmental and intracontinental metallogenic system, and the Mojiang-Lvchun multi-phase supeiposition arc-rift basin setting and metallogenic system, etc. Series super large-large tin, gold, iron, copper, lead, zinc, nickel and other polymetal deposits ore concentration area are formed in this area. Source

Wang L.,Gold Geological Institute of China Armed Police Force | Wang L.,China University of Geosciences | Wang L.,National Research Center for Geoanalysis | Wang Y.,National Research Center for Geoanalysis | And 3 more authors.
Environmental Earth Sciences

The concentrations of heavy metals (Cr, Co, Ni, Cu, Zn, Pb, Cd, As, Hg, and Fe) in sediments of the Yangtze River, China, were investigated to evaluate levels of contamination and their potential sources. The lowest heavy metal concentrations were found in the source regions of the river basin. Relatively high concentrations of metals, except Cr, were found in the Sichuan Basin, and the highest concentrations were in the Xiangjiang and Shun'anhe rivers. All concentrations, except Ni, were higher than global averages. Principal component analysis and hierarchical cluster analysis showed that Zn, Pb, As, Hg, and Cd were derived mainly from the exploitation of various multi-metal minerals, industrial wastewater, and domestic sewage. Cu, Co, and Fe were derived mainly from natural weathering (erosion). Cr and Ni were derived mainly from agricultural activities, municipal and industrial wastewater. Sediment pollution was assessed using the geoaccumulation index (I geo) and enrichment factor (EF). Among the ten heavy metals assessed, Cd and Pb had the highest I geo values, followed by Cu, As, Zn, and Hg. The I geo values of Fe, Cr, Co, and Ni were <0 in all sediments. EF provided similar information to I geo: no enrichment was found for Cr, Co, and Ni. Cu, Zn, As, and Hg were relatively enriched at some sites while Cd and Pb showed significant enrichment. © 2013 Springer-Verlag Berlin Heidelberg. Source

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